Overcasting sewing machine



Sepp-1s, 1936.

F. EBERT ovERcAsTING SEWING MACHINE Filed Feb. 26, 1954 5 Sheets-Sheet l swf.` 15, 1936. F. EBERT 2,054,498

OVERCASTING SEWING MACHINE v Filed Feb. 26, 1934 3 Sheets-Sheet 2 F. EBERT 054,498

OVER CASTING SEWING MACHINE Sept. 15, 1936.

Filed Feb. 26, 1934 5' Sheets-Sheet 3 Patented Sept. 15, 1936 UNITED STATES PATENT OFFICE Fritz Ebert, Oberndorf-on-the-Neckar (Wurttemberg), Germany Application February 267 1934, Serial No. 713,034 In Germany March 8, 1933 8 Claims.

The invention relates to a high speed overcasting sewing machine, i. e. a sewing machine of which the speed of rotation is increased to 5000 revolutions per minute. The technical and economical advantage of the sewing machine accord- -ing to the invention is that in spite of the increased speed of rotation a considerably thinner or inferior thread can be used than is possible with known machines. Y

Thus, for example, even No. 100 needle threads can be used, and it is even also possible to use wool for the needle thread.

These advantages are attained by a novel 15 needle and looper thread control mechanism. Although hitherto the binding of the seam could be controlled only to a limited extent by means c of the thread draw-off lever, it is possible, with the sewing machine according to the invention, to effect control through a wide range by shifting 2o both the oscillatory thread eyes, and adjusting the stationary thread eyes used for control of the thread, in such a manner that the binding may be effected at any desired part or place. On

25 account of the ne degree of adjustment of the action on the threads, a breakage of the thread is to a large extent prevented, and thus a considerable increase in output is attained. The threads are much more gently controlled and thus the causes of the most frequent troubles are avoided from the outset.

The ne control of the needle thread according to the present invention is effected by adjusting vtwo draw-01T hooks oscillating in a closed path, 'while the two looper threads are controlled by a double eye oscillating with the needle lever` and a thread eye oscillating with the looper lever. The double eye is longitudinally adjustable for thread control purposes.

4 The draw-off hooks are suitably arranged on the drive link of the needle lever and co-operate with three stationary thread eyes forming a set functioning as two pairs of eyes. The two drawof hooks so take up the superfluous thread on the withdrawal of the needle from the material and then again on the movement downward of the needle, that a perfect entry of the needle thread into the material is attained. One of the drawoff hooks draws the thread necessary for each stitch from the pre-tensioning means. It is therefore not necessary for the needle to draw the thread from the bobbin or even from the pretensioning means, this thread being supplied to it by the two draw-off hooks.

To control the looper threads by means of the oscillatory double eye and the thread eye, there is provided a common initial draw-off and a further thread control. With the initial draw-ofi located on the front of the machine, the two looper threads run in from both sides, in opposite directions, through stationary thread eyes and are 5 controlled by the thread drawing member actuated by the needle lever and provided with two thread eyes. This member draws thread from the-spools when the two loopers move towards the needle, while the thread is released on the return of the loopers. Y Y Y In the actual thread control also, the two looper threads are controlled by a common member which effects the binding, and this from the lower looper. On the boss of a lever operating this looper is an adjustable ring which carries two adjustable thread eyes which each oscillate between two stationary thread eyes. These thread eyes release thread and take or draw up so much thread as is required by the loopers in their next 20 movement to the needle. Both the oscillating and the iixed thread eyes according to the present invention are adjustable, in order to be able to place the binding at any desired position.

Finally, by the arrangement of a thread pro- L l tecting tube and a return roller for the upperl looper thread, care is taken that this thread is carried to its looper as free from friction or accident as possible.

In the accompanying drawingsz- Fig. 1 is a part sectional front elevation of a sewing machine according to the invention, the table housing being open and unessential parts being omitted,

Fig. 2 is a side elevation of the needle thread 35 control means, and of the looper thread draw-off,

Fig. 3 is a plan view of the mechanism shown in Fig. 2,

Fig. 4 is a 'plan View of the looper thread control means, and

Fig. 5 is a section through the thread eyes of the looper thread control means.

With respect to the stitch formation and thread binding, the overcasting sewing machine according to the invention is of known character, that is, there are two loopers, a lower looper I and an upper looper 2, which co-operate with a needle 3. This is driven by the drive 4 through a link 5 and moved up and down by the usual needle lever 6.

According to the invention, novel cooperating 5o needle thread and looper thread control mechanisms arranged with preliminary draw-off, are provided. The control mechanism for the needle thread 1 consists .substantially of two thread draw-off hooks 8 and 9, which co-operate with 'I'he draw-off hooks 8 and 9 are arranged at the top on the driving link 5 and carry out the movements thereof. By loosening screws 44 (Fig. 2)

the hooks 8 and'9 may be adjusted upwardly and downwardly. They are curved and have the shape shown in Fig. 2.

The hooks 8 and 9 are off-center from the upper pin 5.a and receive a motion compounded of an arcuate oscillation about the axis of the pin 5a and an up and down reciprocation from the crank 4a through which the drive actuates said link. This motion of the hooks is thus along a looped or closed path.

- The three stationary thread eyesI, II and I2 constitute a set functioning as a pair of double eyes and are tted on a common base plate I3 vthe iixed eyes I0, II and I2 and cooperate with them in such manner that when the needle 3 leaves the material, the draw-off hook 8 takes up the needle thread 'I released from the draw-off hook 9, that is, draws it in, by drawing it downwards between the two eyes I6 and II. At the same time, however, the hook 8 draws the thread from the preliminary tension 38 or from the spool, `so that the needle 3 may have supplied to it the thread 'I necessary for each stitch. When Vthe needle 3 has reached its upper turning point,

Y far drawn in and taken upl by the draw-oil hook V9 as is not required by the downward moving needle 3. Furthermore, on account oi the special form of the draw-oir hookS, when the needle 3 has again run past its lowest point the needle thread 'I is still further drawn in, whereby a perfect entry into the work is attained.

The preliminary draw-off of the two ,looper threads I6 and I'I, of which the thread I6 runs Vto the lower looper I and the thread Il to the upper looper 2, is tted on the front of the machine on the frame i5, so that both the draw-01T and the threads i6 and Il' are easily accessible. The control of the preliminary draw-olf takes place from the needle lever E. To this end, there is arranged on this a further lever arm I8 which carries a rod I9 bent at right angles with `two thread eyes 20 and 2|, and thus swings up and down with the needle lever 6. This thread drawoiT, that is, the double eye 29, 27| swings between two stationary eyes 22, 23 and 22", 23 which are ona rod 24 bent into U-shape which is fixed on the frame I 5 of the sewing machine. The two looper threads I6, I'I Vpass through the stationary eye 22 and 23 to the eyes 29, 2| swingingbe- `tween them, and then through the eyes 22I and 23 to the thread control means. The two threads I6 and II thus run, from opposite sides tothe preliminary draw-off as shown in Figs. l and 3. This draws threads oli the spools'when thetwo loopers I and 2 move towards the needle 3, while the threads I S, I'I on the return of the loopers I, 2 are again released. The eyes Y29, 2|, 22, 23 and 22', 23 are adjustable. The oscillating double eye carrierV I9 may be adjusted axially in the lever arm I8 by loosening the iixing screw 25, and the stationary eye carrier 24 maybe adjusted upwardly and downwardly by loosening a fixing screw 28. The latter takes place by thebase plate 26 of the eye carrier 24 being adapted to be moved up and down by means of a vertical slot 21.

The looper thread control is eiected by the movement'of a member which directly undertakes the binding of the threads. In the example shown, the boss 36 of the looper lever 31 of the lower looper I, is used for this (Figs. 1 and 4), and the control of the two threads I 6 and II is carried out by two oscillating eyes 29 and 30 which each co-operate with two stationary eyes 3|," and 32. The oscillating eyes 29 and 30 are on 'arms 33 and 34 which are ttted on a ring 35 fastened on the boss 33 of the lower looper 3l. The lower looper thread Ilapasses through the stationary eyes 3| and the intermediate eye 29, which oscillates up and down between the two eyes 3| and runs to the bottomV looper I, while the upper looper thread I'l runs through the xed eyes 32 and the intermediate eye 33, which osis again taken up and at the same time so much thread is drawn off through the thread tensioning discs 38 as the two loopers I and 2 again require on the next movement. Y

The thread eyes 29, 3| and 39, 32Yare adjustable. Thus the oscillating eye holders 33, 34 can be axially adjusted after loosening the fixing screws 39, and the stationary eyes 3|, 32 can be adjusted laterally. means of a common slot 4U and two iixing screws 4I.

'I'he bottom thread I6 runs from the stationary eyes 3| through a protecting tube 42, at the outlet end of which and at the turning point of their.

bottom thread I6 there is a loose guide roller 43.

I claim:

1. In an overcasting sewing machine with two loopers cooperating with a needle and levers for oscillating the needle and loopers, thread control The latter takes place by oscillating means, a double eye acting upon the 'fr threads supplied to the two loopers, means forr oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, and means for oscillating the separate thread eyes from the looper lever. Y

2. In an overcasting sewing machine with two loopers cooperating with a needle and levers for oscillating the needle and loopers, thread control mechanism comprising a pair of draw-off hooks operative on the thread supplied to the needle, means for oscillating said hooks in a closed path, a set of three stationary eyes traversed bythe needle thread arranged with the two draw-off hooks oscillating in the spaces between said stationary eyes, means for adjusting the draw-oil? hooks in said oscillating means, a do-uble eye acting uponr the threads supplied to the two loopers, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, and means for oscillating the separate thread eyes from the looper4 mechanism comprising a pair of draw-oit hooks operative on the thread supplied to the needle, means for oscillating said hooks in a closed path, means for adjusting the draw-off hooks in said oscillating means, a double eye acting upon the threads supplied to the two loopers and forming a preliminary draw-off for the looper threads which run to said double eye from opposite sides, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, and means for oscillating the separate thread eyes from the looper lever.

4. In an overcasting sewing machine with two looopers cooperating with a needle and levers for oscillating the needle and loopers, thread control mechanism comprising a pair of draw-off hooks operative on the thread supplied to the needle, means for oscillating said hooks in a closed path, means for adjusting the draw-01T hooks in said oscillating means, a double eye acting upon the threads supplied to the two loopers, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, meansl for oscillating the separate thread eyes from the looper lever, and pairs of stationary eyes, each pair cooperating with the two said oscillatory separate eyes.

5. In an overcasting sewing machine with two loopers cooperating with a needle and levers for oscillating the needle and loopers, thread control mechanism comprising a pair of draw-01T hooks operative on the thread supplied to the needle, means for oscillating said hooks in a closed path, means for adjusting the draw-oil hooks in said oscillating means, a double eye acting upon the threads supplied to the two loopers, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, means for oscillating the separate thread eyes from the looper lever, and a ring carrying the Separate thread eyes and adjustable relatively to the fulcrum of the looper lever.

6. In an overcasting sewing machine with two loopers cooperating with a needle and levers for oscillating the needle and loopers, thread control mechanism comprising a pair of draw-off hooks operative on the thread supplied to the needle, means for oscillating said hooks in a closed path, means for adjusting the draw-off hooks in said oscillating means, a double eye acting upon the threads supplied to the two loopers, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, means for oscillating the separate thread eyes from the looper lever, and pairs of stationary eyes, each pair cooperating with the two said oscillatory separate eyes, and said pairs of stationary eyes being laterally adiustable.

'7. In an overcasting sewing machine with two loopers cooperating with a needle and levers for oscillating the needle and loopers, thread control mechanism comprising a pair of draw-off hooks operative on the thread supplied to the needle, means for oscillating said hooks in a closed path, means for adjusting the draw-01T hooks in said oscillating means, a double eye acting upon the threads supplied to the two loopers, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, means for oscillating the separate thread eyes from th looper lever, and pairs .of stationary eyes, each pair cooperating with the two said oscillatory separate eyes, said pairs of stationary eyes being laterally adjustable and mounted in a common groove in the frame of the sewing machine.

8. In an overcasting sewing machine with two loopers cooperating with a needle and levers for oscillating the needle and loopers, thread control mechanism comprising a pair of draw-oil hooks operative on the thread supplied to the needle, means for oscillating said hooks, means for adjusting the draw-01T hooks in said oscillating means, a double eye acting upon the threads supplied to the two loopers, means for oscillating the double eye from the needle lever, separate thread eyes acting on the looper threads, and means for oscillating the separate thread eyes from the looper lever. f

FRITZ EBERT. 

